-LRB- CNN -RRB- -- Crew members on a U.S.-flagged ship learned Friday that their questioning by Venezuelan investigators in an arms trafficking probe has been delayed until Monday .

Venezuelan authorities have held the ship in Maracaibo since August 29 , and took its captain into custody on Wednesday .

The shipping vessel 's crew had expected to give depositions on Friday , according to a crew member who asked to remain anonymous because of security concerns .

As of Friday night , prosecutors had yet to make a decision on the case , according to a manager of the ship 's customs brokers . The manager asked not to be named because of the sensitivity of the situation .

The captain and crew members were all expected to give statements to investigators , the manager said . The crew member who asked to remain anonymous said there were 14 crew members on board , plus the captain .

Divers and drug investigators were inspecting the ship , and the captain was expected to be returned to move the ship from the docks to an anchorage in Maracaibo Bay on Saturday morning , the manager said Friday night .

The manager identified the captain as Jeffrey Michael Raider , 45 , of Texas .

The crew member who asked to remain anonymous said via e-mail Saturday night that the captain in fact had been returned to the ship to command it during its move to anchorage in the bay .

The captain '' is going back tonight . Every bit of news is speculative at this point , '' The crew member said in the Saturday night e-mail .

U.S. State Department spokesman Patrick Ventrell on Friday confirmed the ship and crew 's detention .

`` We understand this has to do with questions about customs paperwork for some rifles they had on board for self-protection , '' Ventrell told reporters . `` We , of course , know that the high seas and that piracy have been a major topic in recent months and years , and so that 's something we 've been combating . And indeed , it 's normal for many ships to have some type of self-defense on board . ''

U.S. officials are seeking more information on the case , and Ventrell said that the absence of a U.S. ambassador in Venezuela is n't hampering the American response . U.S. President Barack Obama nominated an ambassador for Venezuela in 2010 , but the Caracas government would n't allow him to assume the post .

There is an active U.S. embassy in the country , however , and U.S. consular officials did visit the ship 's crew members on Thursday night , according to the crew member .

`` We still have a large mission in Venezuela with appropriate consular personnel , '' Ventrell said . `` I do n't want to get into hypotheticals about what our relationship could be with Venezuela . We are where we are , and we 'll continue to raise it as appropriate through diplomatic channels . ''

The Venezuelan Embassy in Washington said that `` this issue is being handled by our officials in Venezuela '' and did n't have additional immediate comments Friday , spokeswoman Marielba Alvarez told CNN on Friday .

Officials in Venezuela , meanwhile , did not respond Friday to requests for comment .

Soldiers boarded the ship Wednesday , herded the crew into the mess and met with Raider before taking him away , the crew member who asked to remain anonymous said by e-mail Thursday evening . Arrest warrants have been issued for the entire crew , according to this crew member , who added that he believes that authorities mostly want to talk to the crew for depositions .

The situation appeared tense , but the manager of the ship 's customs brokers said the government 's actions have not been aggressive and that both sides are cooperating and being respectful .

`` It 's a legal process , but no one 's rights have been violated , '' the manager said .

The crew member , in another e-mail to CNN on Friday , said that though his colleagues were upset , no one had been mistreated .

`` To be clear , at no point have we been threatened with physical injury , harm or death or had a gun pointed directly at our person . At all times the guns were pointed at the ground , '' the crew member said .

The customs brokerage manager said he had never seen a situation in which a ship was detained and searched in such a way , `` but the authorities of this country must have their motives '' for doing so .

In his Friday e-mail , the crew member gave a detailed account of what had happened since the ship docked in Maracaibo on August 29 .

A few hours after the ship arrived , it was boarded by officials from Interpol , Venezuelan police officers and narcotics investigators who said they had received a tip that the vessel was smuggling drugs , the crew member said .

Members of two separate agencies searched the ship , including the crew members ' rooms , with dogs .

Then the Venezuelan authorities had the crew unload all the ship 's cargo so they could search it , and again did n't find any contraband , the crew member said . At a previous Venezuelan port , authorities sent divers twice to inspect the ship 's hull .

But the officials did find weapons that the ship 's security team keeps in a locker for travel through areas known for piracy , like the Gulf of Aden .

The captain had declared the weapons on arrival in Maracaibo and got cleared to have them , according to the crew member . But the Venezuelan authorities said the ship did n't have permission to have them and confiscated them , he added .

The guns are locked in a bonded area , and they are only for the use of the security company that owns them , the crew member said .

On September 1 , the crew was told the ship was under investigation for arms trafficking , and on Wednesday morning , the captain said the ship 's crew was officially charged .

The captain made a court appearance during the day Wednesday , September 5 , and returned to the ship . That night , 20 to 30 armed soldiers demanded to be let aboard and left with the captain , the crew member said . The captain has n't been back to the ship since , the crew member said , but he has talked on the phone to the chief mate .

The sister of another crew member , who has been in regular contact with her brother and asked not to be identified for security reasons , said crew members have heard that the captain was charged with arms trafficking . The captain was detained after he refused to let authorities arrest the crew , she said .

The customs manager said he expects that the process will play itself out and that the captain will be able to show he had declared the weapons .

`` We are in contact with the government of Venezuela on the matter , and are working to provide all appropriate consular assistance at the earliest opportunity , '' said a U.S. State Department official who spoke on condition of anonymity .

The Ocean Atlas , built in 2000 , is a 393-foot-long multipurpose vessel with two electro-hydraulic cranes and a grain and bale capacity of 395,000 cubic feet , according the website of Intermarine , a managing agent of vessel operating companies .

An Intermarine spokesman was n't immediately available for comment Friday .

The crew member who has been in contact with CNN lauded his union 's efforts Saturday .

`` One of the silver linings of out situation is seeing how our union , the Sefarers International Union , has really come for through for its members , '' he said . `` From the beginning , they were the first ones fighting for us and are working 24/7 to make sure this situation is resolved as soon as possible . ''

The crew member said life aboard the ship is tolerable , within limits .

`` The mood is OK , '' he said . `` Nobody feels scared of physical harm . We just want to go home . Maybe we are wearing thin on the edges a little , but nothing bad . ''

CNN 's Mariano Castillo , Catherine Shoichet , Elise Labott and Marilia Brocchetto , and journalist Osmary Hernandez contributed to this report .

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NEW : Captain returned to vessel to move ship from docks , source says

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U.S. official says incident is about paperwork for rifles they had aboard for protection

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The crew 's scheduled depositions are pushed back to Monday , a crew member says

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A manager of the ship 's customs brokerage firm identifies the captain as Jeffrey Raider